[email protected] _ HAEMOPOIESIS LS 5-1.pdf

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1. MODULE – 2

2. LEARNING SCHEDULE – 3

3. LEARNING OBJECTIVES – (LS-3):
1.To know the components of blood
2.To know the morphology or constituents of the
components of blood
3.To have knowledge the functions of each of the
components of blood

4. Components of blood and functions

5. Components of blood and functions
Components:
1. Blood cells:
•a. Erythrocytes (red blood cells, RBCs)
•b. Leukocytes (white blood cells, WBCs)
•- Granulocytes (Neutrophils, Eosinophils, Basophils)
•- Agranulocytes (lymphocytes, monocytes)
•c. Thrombocytes (platelets)
2. Plasma
Question: What is serum?

6. Components of blood and functions

7. Components of blood and functions
A normal haemogram would have the following values
RBCs
Male 5-6x 10^12/L
Female 4-5x 10^12/L
Hb
Male 13-18g/dL
Female 11.5-16g/dL
Reticulocytes: 0.8-2%
• Platelets 150-400 x 10^9/ L
• WBCs 4-11x 10^9/L
Neutrophils: 40-75%
Lymphocytes: 20-45%
Monocytes: 2-10%
Eosinophils: 1-6%
Basophils: 0-1%

8. Components of blood and functions

9. Components of blood and functions

10. Erythrocytes or Red Blood Cells

11. Erythrocytes
•Red Blood cells or Erythrocytes are anucleate cells
•They function in the transportation of oxygen to tissues and
carbon dioxide to from cells and tissues to the lungs for
gaseous exchange
•They contain Haemoglobin (Hb) a protein, which gives them
the red colour and Iron containing heme pigment
•Mature forms are anucleate
•They have a life span of 120 days

12. •Blood volume is 6 -8 % of body
weight
•The % of blood volume occupied
by RBCs is known as the Packed
Cell Volume or PCV
•The RBCs may be referred to as
Normochromic, Hypochromic or
Hyperchromic depending on the
Hb affinity
•Differences in sizes is known as
Anisocytosis
•Differences in shapes is known as
Poikylocytosis

14. HAEMOGLOBIN
•Haemoglobin is the respiratory protein in the
red blood cells of vertebrates.
•Its physiological functions are to transport
oxygen from the lungs to the tissues and to
facilitate the transport of carbon dioxide
from the tissues to the lungs.
•Haemoglobin has molecular weight of about
64,500 and comprises four subunits, each
having one polypeptide chain and one
prosthetic group, the haem.

15. Erythrocytes

16. •The haem group is a protoporphyrin ring at
the centre of which is an iron atom in the
ferrous state.
•In free haem the ferrous iron atom is
oxidized to ferric by reaction with oxygen
•In haemoglobin the iron atom combines
reversibly with oxygen and stays in the
ferrous state in both the oxygenated and
deoxygenated forms.

17. •This reversible combination with oxygen is
made possible in haemoglobin by the folding
of the polypeptide chains around the haem
groups to enclose them in hydrophobic
pockets.
•The four polypeptide chains are of similar
length. Two identical chains, the Alpha-
chains,each contain 141 amino acids and two
other identical chains, the/3-chains, each
contain 146 amino acids.

18. •Haemoglobin reacts reversibly with oxygen
at the four haem groups.
•It picks up oxygen in the lungs, where the
oxygen tension is high, and releases it in the
tissues where the oxygen tension is low.
•In muscle the oxygen is taken up by
myoglobin which is a single subunit
respiratory protein containing only one haem
group.

19. HAEMOGLOBIN TYPES

20. ABNORMAL HAEMOGLOBIN

21. HAEMOGLOBIN

23. Erythrocytes
•Old RBCs are sequestered by the Spleen and Bone marrow
by phagocytes (Reticulo-endothelial System)
•The Heme iron is re used
•Hb is degraded to bilivedrin then bilirubin
•Bilirubin is conjugated with Glucuronic acid in Liver to a
less toxic conjugated bilirubin stored as bile in the gall
bladder

25. Erythrocytes

26. Erythrocytes

27. Leukocytes

28. Leukocytes

29. Leucocyte diapedesis in inflammation

30. Neutrophils
•Multi lobed cells
•Often called Polymorphonuclear Leukocytes PMNs

31. •Usually most abundant White cells
•Important role in inflammation
•Phagocytosis, production of Reactive Oxygen Species,
release cytotoxic granule contents
•They release cytokines and chemokines that initiate and
amplify inflammation

33. Neutrophils
•Neutrophils develop from
•Myeloblasts
•Promyelocytes
•Myelocytes
•Metamyelocytes
•Band Cells
•Mature Neutrophils
•Pre mature neutrophils can be released into circulation in times of
infection and inflammation
•Neutrophilia is indicative of bacterial infections

34. Eosinophils
•Bilobe with abundant eosinophilic granules (azurophilic)
•Acid loving
•Important mediators for allergic responses
•Aid in parasitic infections
•Produce cationic granule proteins
•Reactive oxygen Species
•Enzymes
•Growth factors (TGF, Vasoendothelial Growth factor, )
•Cytokines like IL-1, -2, -4,-5, -6,-8, -13 and TNF Alpha
•Eosinophilia seen in parasitic infections, Allergic response,

35. Basophils
•Constitute less that 1% of WBC count
•Rarely seen on PBS
•Course large granules, bi lobed
•Important role in hypersensitivity
•Release heparin, histamine, proteases, IL 4

36. Monocytes
•These are the largest WBCs
•Agranular with clear
cytoplasm
•Bean or kidney shaped
nucleus
•Motile and phagocytic like
Neutrophils
•Migrate to tissues to
become Macrophages
•Secrete Platelet Activating
factor, Interleukin-1

37. Monocytes
•Are agranulocytes that are precursor cells of the
mononuclear phagocyte system:
•1. Macrophages in extravascular space
•2. Osteoclasts in bone
•3. Microglia in CNS
•4. Kupffer cells in liver
•5. Langerhan’s cells in the epidermis of the skin
•6. Other APCs in connective tissue
• All monocyte-derived cells are antigen-presenting
cells (APCs) or dendritic cells and have important roles in
immune defence of tissues

38. Lymphocytes
Most numerous type of agranulocyte in normal blood
smears or complete blood counts (CBCs)
• Spherical nuclei
• As the cells mature, the original nuclear to cytoplasmic
ratio (NC ratio) is almost retained or decreases slightly
• Typically the smallest leukocytes
• Can be subdivided into functional groups by distinctive
surface molecules
• These surface molecules are called “cluster of
differentiation” or CD markers
• These can be distinguished using antibodies with
immunocytochemistry or flow cytometry

39. Lymphocytes

40. •Divided into:
1. B lymphocytes > Plasma Cells (produce Anti-bodies)
2. T-Lymphocytes
•- Helper T cells: CD4+
•- Cytotoxic T cells: CD8+
•- Memory T-cells
•- Suppressor or regulatory T-cells
3. Natural killer (NK) cells

41. Platelets
•Very small non-nucleated, membrane-bound cell
fragments (2-4 μm in diameter)
•Originate by separation from megakaryocytes
•Promote blood clotting and help repair minor tears
or leaks in the walls of small blood vessels,
preventing loss of blood from the microvasculature
•Circulating platelets have a life span of about 10
days

42. Platelets

43. •A sparse glycocalyx surrounding the platelet
plasmalemma is involved in adhesion and
activation during blood coagulation
•Ultrastructural analysis reveals a peripheral
marginal bundle of microtubules and
microfilaments
•This bundle helps to maintain the platelet’s shape
•Platelets contain actin and myosin filaments and
thus are contractile

44. LEARNING OUTCOMES – (LS-1):
1.Students should know the composition of
blood and its various functions
2.Students should be able to name and explain
the structure of Blood cells
3.Students should know the functions of Cells
and their importance in disease